Valve for rock drills



July 20 1926. 1,592,855

G. W. HULSHIZER VALVE FOR ROCK DRILLS Filed June 20, 1925 INVENTOR .B AU Georg/e m r/513%? W HIS ATT NEY Patented July 20, 1926.

UNITED STAT ES PATENT QFFICE.

GEORGE W. HULSHIZEB, 0F STEWARTSVILLE, NEW JERSEY, ASSIGNOR TOINGERSOLL- RAND COMPANY, 01' JERSEY CITY, NEW JERSEY, A CORPORATION 01NEW JERSEY.

VALVE FOB 360K 133E148.

Application filed June 20, 1825. Serial No. 38,442.

This invention relates to fluid actuated rock drills, but moreparticularly to a spool type distributing valve for rock drills of thehammer type.

One object of the invention is to enable a rock drill to be equippedwith a valve so constructed as to prevent centering of.

said valve.

Another object is to produce a valve f the spool type which is quick andsensitive in operation and positive in its action.

Other objects will be in part obvious and in art pointed outhereinafter.

he invention consists of the combinations of elements, features ofconstruction and arrangement of parts having the general mode ofoperation substantially as hereinafter' described and more particularlypointed out in the. appended claims and illustrated in the accompanyingdrawing, in which- 7 Figure 1 is a longitudinal view in eleva tion andpartly in section of so much of a rock drill as will serve to illustratethe invention,

Fi are 2is a view similar to Figure 1 and in w rich the reciprocatoryparts are shown in another position.

Referring to the drawing, the invention is shown embodied in a rockdrill having a cylinder A in which is arranged a reciprocatory piston Bfor deliverin blows on a drill steel (not shown). A :ront cylinderwasher C is disposed within the front end of the cylinder A and has abore D to receive slidably a fluted forward extension E of the piston13. The back end of the cylinder A is sealed by a back cylinder washer Fwhich also serves to centralizea back head arranged at the back end ofthe cylinder A. Any. suitable means may be provided tor securing theback head G to the cylinder A, but such means preferably consist of siderods or bolts (not shown) arranged on opposits sides of the drill.

Rotary motion of the piston B is in this instance accomplished by arifle bar, H which engages the piston B in the usual manner. A ratchethead J preferably formed integral with the rifle bar H carries aplurality of spring actuated pawls K. The anda K are so arranged thatthey will pass freely over teeth L formed in a ratchet chest Qcomprising a bottom plate It and a top late or cap S. A throttle valveT, referab y arranged within the ca S o the valve chest Q, controls thea pressure fluid to the machine. The pressure fluid is exhausted fromthe cylinder A through a free exhaust port U preferably formed in thecylinder intermediate its ends and is controlled by the piston 33.

In accordance with the present invention, a pressure chamber V is formedin the cap S and a similar chamber W is formed in the plate R to receivea distributing valve X. The valve X is of the spool type and has acentral flange Y extending at its periphe into an annular supply chamberZ whic communicates with the throttle valve T through passages R and Sformed in the plate and the cap S respectively. In this instance sidesI) and c of the flange constitute actuating and holding faces againstwhich pressure fluid may act for throwing the valve and for holding itin thrown position. In addition to serving as actuating and holdingfaces, the faces 5 and 0 also control the admission of pressure fluid tothe rear and front ends of the cylinder through supply passages'd and erespectively.

In order to facilitate throwing of the valve in one direction, a passage7 is formed from the forward end of the cylinder A to the chamber W foradmitting pressure fluid from the cylinder into said chamber to actagainst a face 9 for augmenting the pressure fluid acting against theface E) of the flange Y for throwing the valve and holding it in thrownposition. A similar pas- 'ssion of sage 71, rovides communicationbetween the rear on of the cylinder A and the chamber V for admittingpressure fluid into said chamber to act against a face 9' at the otherend oi'the valve for augmenting the ressure fluid acting against theface 0 o the flange Y for throwing the valve to its opposite positionand for holding the valve in thrown position.

In order to further facilitate the throwing of the valve, a plurality ofsmall passages 7c are formed through the flange Y to communicate attheir ends with annular passages o and p formed in the cap S and theplate R res ectivelyto encircle the pressure chambers R and W. In thisinstance, passages q and 7' leading from the chambers V and Wrespectively to the atmosphere are formed in the valve chest to preventthe forming of a cushion while the valve is be-' ing thrown.

In the operation of the device, with the parts shown in the osition inFigure l, pressure fluid flowing om the throttle valve T into theannular chamber Z will pass over the face 0 of the valve X and thenceinto the annular passage 0 and through the supply passage e into thefront end of the cylinder ,and drive the piston B rearwardly. During therearward travel of the piston B, the passage f will be uncovered andpermit a portion of the pressure fluid to flow therethrough into thechamber W to augment the pressure acting against that part of the faceI) of the valve X which extends into the annular groove Z for throwingthe valve. After the piston B covers the exhaust port U and while thevalve is still in thelposition shown in Figure 1, the pressure fluileaking through the passages is will flow into the rearward end of thecylinder A. In this way equal pressures are obtained on opposite sidesof the flange Y. Such e ualization of pressures on op osite sides 0 theflan e will cause the va ve to move to a neutra position. As the pistoncontinues rearwardly the pressure fluid acting against the face 6 of theflange Y, assisted by the compression formed in the rear end of the clinder after the passage h is covered by the piston will act against theface I) and throw the valve to the position shown in Figure 2. In thisposition of the valve, pressure fluid will flow across the face of thevalve into the annular passa p thence through the suppl port 4 into t erearward end of the cylindzzr and drive the piston forwardly.

As the piston advances on its forward stroke, the passage k is uncoveredand pressure fluid is admitted into the chamber V to act against theface of the valve.- At the same time, pressure fluid will leak throughthe passages into the annular passage 0 and, as during the rearwardstroke of the piston, augments the compression formed in the front endof the cylinder to act against the face 0 of the flange Y for throwingthe valve in the opposite direction, thus completing the cycle ofoperations.

The advantages of this invention reside in the fact that a valveconstructed in this manner requires only a slight travel to sup plypressure fluid in sufiicient quantities to the cylinder. Anotherdesirable advantage is that the valve is quick and positive 1n action.

I claim:

1. In a fluid actuated rock drill, the combination of a cylinder with areciprocatory piston, a valve chest having pressure chambers, annularchambers encircling the pressure chambers, a valve located in thepressure chambers and annular chambers, actuating and holdin faces ateach end of the valve, a central ange on the valve to control theadmission of pressure fluid from a source of supply to the annularchambers, and supply passages affording communication between theannular chambers and the ends of the cylinder for conveying pressurefluid to the cylinder.

2. In a fluid actuated rock drill, the combination of a cylinder with areciprocatory iston, a valve chest having pressure chamers, annularchambers encircling the pressure chambers, a valve located in thepressure chambers and annular chambers, actuating and holding facesateach end of the valve, a single flange on the valve to control theadmission of pressure fluid from asource of supply to the annularchambers, actuating and holding faces on each side of the flange againstwhich pressure fluid may act for throwing the valve and holding it inthrown position, and supply passages affording communication between theannular chambers and the ends of the cylinder for conveying pressurefluid to the c linder.

3. In a fluid actuated rock drill, the combination of a cylinder with areciprocatory piston; 91 valve chest having pressure chamers, annularchambers enclrcling the pressure chambers, a valve located in thepressure chambers and annular chambers, actuating and holding faces ateach end of the valve, a single flange on the valve to control theadmission of pressure fluid from a source of supply to the annularchambers, actuating and holding faces on each side of the flange,passages through the flange to rovide communication between the annuarchambers, and supply passa es leading from the annular chambers to t ecylinder for conveying pressure fluid to the c linder.

4. In a fluid actuated rock drill, t e combination of a cylinder with areciprocatory iston, a valve chest having pressure chamrs, annularchambers enclrcling the pressure chambers, a valve located in thepressure chambers and annular chambers, actuating and holding faces ateach end of the valve, a sin 1e flange on the valve to control theadmission of pressure fluid from a source of supply to the annularchambers, actuatin an olding faces on each side of the ange, passagesthrough the flange for .the admission of pressure fluid therethrough toequalize the pressure on both assages leading from the pressurechamsides of the flange, supply passages leading ers to the atmosphereto prevent cushionfrom the annular chambers to the ends of in in thatchamber toward which the valve 10 the cylinder, passages controlled onlyby the is eing thrown.

piston for conveying pressure to the pres- In testimony whereof I havesigned this sure chambers to facilitate reciprocation of specification.the valve and for holding the valve, and GEORGE W. HULSHIZER.

